Technical Abstract:
High hydrodynamic pressure has been considered as a new novel food processing technique to impart favorable textural changes in meat. It is believed that a hydrodynamic pressure wave could be used to tenderize otherwise unacceptably tough cuts of beef, and allow them to be used in more valuable products. Currently, very little work has been reported in study of the effect of HDP treatments on the quality of various meat products by means of mathematical modeling. A mathematical model for predicting the deformation history of a protein gel under cyclic loading of a shear stress was developed. A four-element Burger model was used as the starting point for the model, and expanded to consider stress and strain responses in the product under a varying pressure. The creep recovery and stress relaxation response of the gel allowed prediction of the deformation in each term of the model, and therefore the overall deformation. Values for the storage and loss modulus of the product were taken from behavioral studies of B-lactogloublin protein gels. Model sensitivity showed that low frequency oscillations and decreased storage modulus values dominated deformation behavior. The model was entirely non-sensitive to frequency changes above 30,000 rad/s. Values for deformation of the gel were calculated for a spectrum of frequencies between 30,000 rad/s and 300,000 rad/s, under low pressures (50,000 Pa). There appeared to be some harmonic resonance between the applied pressure frequency and the loss tangent of the gel, resulting in a family of frequencies that caused the greatest deformation.